Dyno chart

[Richard. Wales UK]

Hi Steve

The guy who did the reflash on mine said the flies perform an important job, especially at lower revs, and their removal will affect the power delivery and smoothness / drivability of the engine.

He couldn't dino thun mine because he only had a bike dino, which is no good for my trike :-(

[VirginiaJim]

All's you gots to do is ask the ones that have removed them flies if they've affected the bike negatively...  I think that most of them would say not...even the ones with TC..

My bike is bone stock in the fly dept and it has all the power I need when I need it.   Have an Area P.  Coming up I95 today I  kept catching myself doing 90+ and then slowing back down..

[connie_rider]

In your opinion what was Kaw's objective in controlling the air flow with the secondary throttle plates?

In Note #19 Steve explained the result he got by controlling the flies. So, I won't go there.

As I sed I'm not an expert. Only a garage mechanic.
I like to study "why" things work.
And I like to learn by discussing those theories.

That being said, I'll guess at "why" the secondary fly is installed in the throttle body...

Air/Fuel mixture...

I suspect that the opening (rate, timing, and amount) effects the velocity and turbulence of air at/after the fly.
(I think) That air movement helps to "better" atomize and mix the air/fuel. (result being a better A/F mixture at low throttle openings).

Ride safe, Ted

PS: Steve; Thanks for your answer on the Slip-on's.
       (I experimented with a baffle in my Area P and definitely lost performance).
          Removed it!

[Steve in Sunny Fla]

All's you gots to do is ask the ones that have removed them flies if they've affected the bike negatively...  I think that most of them would say not...even the ones with TC..

 tTo me, not really the issue... I know the difference now, and flies out might be the best for someone who has never known better, but it's simply not "the best". steve

[maxtog]

tTo me, not really the issue... I know the difference now, and flies out might be the best for someone who has never known better, but it's simply not "the best". steve

I would word it this way- "flies out is a LOT better than stock, and flies in but flies programmed to open faster/more is a little better than flies out + PC."

[maxtog]

Several times you've made comments about the Slip On Mufflers.
From your posts, apparently you don't like them.
Why don't you like them, and how do they work (or not work) with your flash?
{ie; what is the advantage or disadvantage? [not yes they will work or no they won't]}

As an addendum to what Steve said (and I say over and over in many threads), changing the muffler is not changing "the exhaust system".  On a modern bike like the C14, changing the muffler doesn't affect performance much at all, regardless of what you do with the flies or a PC or air filter or anything else other unless it is part of upgrading THE WHOLE EXHAUST SYSTEM.  Changing the muffler [silencer] to something supposedly less restrictive simply moves the pointer to the next restriction in the rest of the system (which is the rest of the pipes and the exhaust manifold... and then there is the intake, intake manifold, and throttle bodies to contend with).  It is like cutting off several feet of garden hose- it doesn't change much of anything until you replace the ENTIRE hose with something larger.  I also read that on the C14 that the cats (catalytic converters) are not a point of much restriction either.

Replace [just the] the muffler if you want to save weight, change the sound, or for asthetics, but not because you think it will change performance in any meaningful way.

The C14 is not a 1970's bike design. 

[maxtog]

(They put the 2nd butterfly in the throttle body for a reason, as it wasn't an inexpensive addition).
I assumed that the Kawasaki (Supplier) added the 2nd butterfly to control flow thru the throttle body.
So, if the butterfly is removed, that control is lost.

Hashed over and over in several threads.  Yes, there were most likely several reasons the flies are there (not just one).  Based on what I have read, my conclusion has been:

1) As part of emissions control, which sacrifices maximum power and responsiveness for improved emissions
2) As part of fuel economy, for more MPG overall
3) As part of noise control, which helps to mute intake noise
4) As part of the traction control system, which helps to smooth the removal and re-delivery of power during and after an "event"
5) To "tame" (neuter/smooth) low throttle response on a large/powerful engine to help with less experienced or more timid riders

And not necessarily in that order, but I suspect emissions control is king.

[Steve in Sunny Fla]

Maxtog, on the issue of the cats not being very restrictive, I'm not so sure about that. I purposefully built a header with the same tube diameter as the stock header, collecting the pipes in the same manner as stock, but without the cats. That bike really came alive, and from low rpm's on up. It also got loud. It was fitted with a 2 bros slip on before and after the header change; the difference in volume was significant. Based on the power gain alone,I'd have to take exception to any statements that indicate the cats aren't restrictive, or aren'taffecting the power output negatively. steve

[Conniesaki]

Maxtog, on the issue of the cats not being very restrictive, I'm not so sure about that. I purposefully built a header with the same tube diameter as the stock header, collecting the pipes in the same manner as stock, but without the cats. That bike really came alive, and from low rpm's on up. It also got loud. It was fitted with a 2 bros slip on before and after the header change; the difference in volume was significant. Based on the power gain alone,I'd have to take exception to any statements that indicate the cats aren't restrictive, or aren'taffecting the power output negatively. steve

Was it faster?

[Steve in Sunny Fla]

yes, obviously so. I've since sold that bike to a fellow Cogger. He's sceduling a trip to the dyno next month to see what the output is. I'll say this, with me on it, if I snap the throttle at 4000 rpm / 2nd gear the front end clears the ground til I shift. the flies are still in, and I haven't flashed that bike, it was all from changing the cam timing and the header. Steve

[gPink]

Steve, I saw where you mentioned a possible flies out/PC5 flash. Is that being developed with or without AutoTune?

[maxtog]

Maxtog, on the issue of the cats not being very restrictive, I'm not so sure about that. I purposefully built a header with the same tube diameter as the stock header, collecting the pipes in the same manner as stock, but without the cats. That bike really came alive, and from low rpm's on up. It also got loud. It was fitted with a 2 bros slip on before and after the header change; the difference in volume was significant. Based on the power gain alone,I'd have to take exception to any statements that indicate the cats aren't restrictive, or aren'taffecting the power output negatively. steve

I should have disclaimed that I have ZERO experience with cat removal that and it was ONLY based on what I read in threads on this board, which seemed to clearly indicate that the flow didn't change much (the diameter is decent, and it is a 2 way/flow-through cat, not a more restrictive 3 way).  Just edited that posting now to indicate it is just what I read.  Of course, I can't find the thread(s) with the info I was basing my info on now, damnit...

[Steve in Sunny Fla]

Steve, I saw where you mentioned a possible flies out/PC5 flash. Is that being developed with or without AutoTune?

Since it would be used with end users pcv, it would depend on the pcv fuel maps either loaded or developed by the autotune on that individual bike. Steve